Stone-boring machine.



No. 717,702. 'PATENTED 'JAN.6,1903. J. P, MURPHY. $770175 BORINGMAGHINE.

APPLIGATION FILED JAN. 6, 1902.

I 1X0 MODEL.

Y1- c D O I e 7 1% .7 GD a j o g I J o b 0 ii 1; lui/eyfof:

' shown.

UNITED STATES PATENT OFFICE. I

JOHN P. MURPHY, OF PORTLAND, MAINE.

STONE-BORING MACHINE.

SPECIFICATION formingpart of Letters Patent No. 717,702, dated January6, 1903.

Application filed January 6, 1902- Serial No. 88,583. (No model.)

To whom it 771.09g concern:

Be it known that I, JOHN P. MURPHY, a citizen of the United States ofAmerica, and a resident of Portland, Cumberland county, State of Maine,have invented certain new and useful Improvements in Stone-BoringMachines, of which the following is a specification.

My invention relates to a machine for boring annular holes in stone, andit is designed particularly for boring out hollow columns and the likefrom granite or other hard stone,

it being provided with a head having cut tin g-blades laterally andvertically adjustable therein, so that difierent-diametered columns anddifierent depths may be produced and also several concentric holes canbe made simultaneously.

With this end in view my invention consists of a vertical shaft, on thelower end of which is a cutter-head carrying vertical blades adapted totravel in the annular groove. The blades may by suitable fastening meansbe adjusted for difierent diameters, and they may be so set as to boreseveral concentric holes at the same time.

I illustrate my invention by means of the accompanying drawings, inwhich- Figure 1 is a front elevation of the machine. Fig. 2 is a planview of the cutterhead, and Fig. 3 is a section on the line 00 a: ofFig. 2.

A represents the framework of themachine, and e is the vertical shaft,held in suitable hearings in the frame, so that it has a longitudinalmotion in its bearings, as herein Power is applied to the shaft by thepulley g, connected to the shaft by means of the spline 1, so that theshaft may move freely in a vertical direction, while the pulley remainsstationary. On the lower end of the shaft is the cutter-head h, hereshown as formed in one piece, with radial arms h, the outer ends of thearms being joined by means of a band or rim. The cutting-blades c' areheld in a vertical position and secured to the radial arms of thecutter-head by means of the clamps J. These clamps are composed of alower block'j, fitting in the radial groove which is formed in each arm,the upper block j bolted to the lower block by the screw j and the upperand lower clamps 7' bolted to the blocks by screws by which the verticalblades are held to the adjustable clamp. The lower edge of the lowerblock has flanges or projections which impinge on the under side of thearm, and the upper block has like flanges, by which the two portions ofthe block are firmly fastened in position on the arm at any desiredpoint. The blades extend up through the slots in the arms and areclamped to the outer face of the blocks by the upper and lower clamps.It will be seen that the clamps may be readily fastened at any point onthe arm, and the blades may be fastened at any point in their height.

For the purpose of taking a portion of the weight of the cutter-headfrom 06 the blades 71 I provideacounterweight 0, connecting with the topof the shaft by means of a cord 11, running over pulleys a a, the end ofthe cord being secured to ayoke d on the upper end of the shaft 6.

The operation of my machine is as follows: The blades'z' are set at therequired point to cut the annular groove desired, and a shallow grooveof the diameter desired is cut in the stone by hand. The stone is placedunder the cutter-head and the blades caused to travel in the groove,chilled-iron shot being placed in the bottom of the groove, as is usualin stone-cutting tools. The blades will cut their way rapidly throughthe stone and take out" a core of any desired diameter up to thecapacity of the machine. In practice I start a groove with short blades,and after getting down into the stone I shift the blades for longerones.

It will be seen that by setting a portion of the blades inside of theothers two grooves may be cut at the'same time of different diameters.Thus two or more hollow columns of different diameters may be cut at thesame time on the machine.

It is evident that the cutter-head may be given a rotary and verticalmotion otherwise than by the means here shown'-as, for instance, byhaving the cutter-head splined to the shaft instead of being securedrigidly to it, as here shown; but such modification would come withinthe scope of my invention.

I claim 1. In a stone-boring machine, the combination of a frame, ashaft mounted revolubly -be held vertically adjustable by the clamp.

2. In a stone-boring machine, the combination of a cutter-head,comprising a series of radiating arms each provided with a slottherethrough, a clamp made in two members one spanning the slot of eacharm and the other entering the slot from below and provided with meansto draw the members together and secure the clamp upon the arm, a fiatblade projecting through the slot of each arm, and clamps adjustablysecured to the firstmentioned clamp for adj ustably securing the blades,so that they can be vertically adjustable.

Signed at Portland, Maine, this 26th day of December, 1901.

JOHN P. MURPHY. Witnesses:

S. W. BATES, HARRY B. Ross.

